The Crooked Creek Water Reclamation Facility is so well maintained that a visitor once mistook it for something else.

“A lady walked up to the gate by accident, not knowing what the facility was, and said she thought she was at a school,” recalls David Jones, plant superintendent.

The modern buildings, well-maintained landscaping, and high-quality effluent have been major factors in the Crooked Creek facility winning the Georgia Association of Water Professionals Plant of the Year in 2022, as well as 2018 and 2020. 

On top of that the plant, operated by the Gwinnett County Department of Water Resources, has attained the Platinum Peak Performance Award from the National Association of Clean Water Agencies for the last 17 years, for having no permit violations.

“What’s special about this plant are the aesthetics and the work being done here,” Jones says. “It’s a beautiful facility. We’re known for a high standard of operation, and a high-quality effluent that’s well below permit requirements. We’re proud of that.”

Part of a system

The Crooked Creek WRF, in Norcross, is one of three wastewater treatment plants serving Gwinnett County, northeast of Atlanta. It’s designed for a dry-weather flow of 16 mgd; average flow is about 8.4 mgd. The plant was designed for reliability, ease of operation and maintainability. “Every process has redundant systems,” says Jones. “It makes life easier!” 

Wastewater enters the treatment train through an influent pump station (KSB pumps), and passes through four grinders (JWC Environmental) before entering the headworks. JWC band screens remove rags and debris, and grit is removed by a PISTA Grit system (Smith & Loveless).

A return/waste activated sludge mixing box follows, after which the flow passes to a pair of side-by-side plugged-flow bioreactor trains, each containing anoxic, anaerobic and seven aerated zones. Howden Roots Turblex blowers provide aeration. Magnesium hydroxide is added ahead of the bioreactors for alkalinity and pH control. Alum is added at the end of biological treatment for phosphorus removal and to aid in settling.

The treated water settles in clarifiers with Tow-Bro headers (Evoqua Water Technologies). Two of the four settlers are in operation at any one time. The clarifier overflow enters a set of automatic-backwash AquaDiamond tertiary cloth filters (Aqua-Aerobic Systems), and then to two Duron UV disinfection channels (Wedeco), each channel containing 108 bulbs. Final effluent passes over a post-aeration step before discharge to the Chattahoochee River.

Handling solids

Biosolids are stored in a pair of aerated tanks, then treated with polymer and dewatered on four 2-meter belt presses (BDP). Cake at 18.2% solids is hauled to landfill. Press filtrate is stored and then metered back to the head of the treatment process. The plant accepts an average of 20 septage trucks a day. Jones says septage has little to no impact on plant nutrient loading.

A new SCADA system was supplied by AVEVA. The computerized maintenance management system is from Maximo (IBM). The plant is moving ahead with plans for operators to have handheld devices, enabling them to complete plant checks and pass down daily activities between shifts.

Crooked Creek is staffed by 14 operators under Jones and Cody Reece, plant manager. A maintenance team keeps the equipment and facilities in top shape. The operations team includes:

• Timothy Kring and Darryl Miles, shift supervisors
• Wastewater technicians Edward Appiah, Philip White, Kevin Young, Danielle Hines, Joel Craig, Rory Cavagnaro, Jackson Rivers, Dionte Ryals, Nicholas Dillon and Maclellan Hicks; interns Alexandria Coffman, Jason King, and Lucy Shuman
• Richard Anderson, trades coordinator; and Donald Loggins, Carl Fincher and Alexander Defranza, trades technicians
• Joey Foss, SCADA technician
• Alex Head, planner/scheduler
• Marlon Parras, warehouse technician

Big renovation

The Crooked Creek plant went through a major upgrade from 2017-21. While the influent station and headworks remained unchanged, the downstream processes underwent major work in a $136 million renovation. The old oxidation ditches were replaced with the new bioreactor system, which improved treatment and added capacity, especially for wet-weather flows.

Two existing secondary clarifiers were retained and upgraded with new equipment, and two new ones were added. While the automatic backwash filters remained the same, the UV disinfection system was new; the open-channel system replaced a pressurized vessel technology.

A new biosolids handling system was added, complete with the four new belt presses. In addition to many structural changes, which required significant earth moving and new concrete, the project involved an overhaul of the plant’s electrical system and controls. The SCADA system, plant switchgear (Emerson), and standby diesel generators (Caterpillar) were all upgraded. 

Keys to success

Jones, who was plant manager at the start of construction, says communication and relationships were essential to the project. His staff took the lead in making things work: “We relied on close cooperation among all parties — our staff, the contractors, the engineers. That was the No. 1 thing. We’ve worked with several of the project team members for years and had established relationships that helped.”

Still, it was sometimes difficult to keep things on track with different minds involved. “We had lots of meetings,” Jones says. “There were shutdowns and bypasses, some of them occurring at three in the morning and lasting for days. We documented everything and had dry runs to make sure we were all on the same page with planning and coordination, preparing for the moment.”

Jones saw the opportunity for his staff to be on site and monitor the changes to the plant as a big plus. The change from oxidation ditches to the bioreactors was a critical event: “Operators were a big factor in the success of the total construction project. Everything depended on trust and communication.”

Pride in performance

Communication with neighbors was also important. An apartment complex borders the plant on one side, and a residential community sits just north of the plant. “Even before the construction, we did an excellent job of controlling odors and operating at a high standard,” says Jones. “Not many of the residents realized the plant was here. The team used signage to make sure traffic ran smoothly during construction. Police officers helped direct traffic at peak times.”

With more than 100 construction workers at the site at any given time, arrangements were made for them to park their vehicles in a nearby church lot. Shuttle buses took them to the work site to avoid traffic jams. Construction crews made a special effort to keep the noise down: “It was a very smooth project all the way around. We were never offline during construction.”

Jones is especially pleased about the Plant of the Year awards — in 2018 as construction began, in 2020 in the middle of the project, and in 2022 when work was complete. Jones believes the awards recognize violation-free performance and reflect the standards the plant has for the documentation of operations and aesthetic value.

Now that the construction dust has settled, new challenges lie ahead. “We’re a fast-growing county,” Jones notes. “We will have to stay ahead of that growth.” PFAS and other emerging contaminants, and the accompanying regulations, also pose a challenge. But Jones feels Crooked Creek will be up to the tasks ahead: “It’s our caring staff.”